Incineration system

ABSTRACT

An incinerator system is provided with a rotary incinerating chamber, a burner for directing flame into the chamber, feed means at one end of the chamber, an exhaust conduit for removing combustion gases from chamber, a secondary combustion chamber connected to the conduit for receiving exhaust gas therefrom and an exhaust stack connected to the downstream end of the secondary chamber. The rotary incinerating chamber is provided with a frustoconical interior surface with the feed end being the smaller diameter end thereof, said incinerator chamber being mounted for rotation about a horizontal axis of rotation for imparting abrasive tumbling movement to waste material feed to said one end by said feed means. The burner is mounted at the feed end for initiating immediate incineration of said waste material and means are provided at the end opposite said one end for removing the solid incinerated material therefrom. The secondary combustion chamber includes a burner mounted for tangential flame discharge at an angle to longitudinal axis of the chamber to provide a cyclonic aspirating gas flow through the conduit from the incinerating chamber. The combustion chamber may be of modular construction.

United States Patent Przewalski Jan. 21, 1975 INCINERATION SYSTEM [57] ABSTRACT lnvemol'i yg Prlewalski, Windsor, An incinerator system is provided with a rotary incin- COflnerating chamber, a burner for directing flame into the [73] Assigneez Progressive Trade Corporation, chamber, feedmeans at one end of the chamber, an

Glastonbury, Conn exhaust condu1t for removmg combustlon gases from chamber, a secondary combusnon chamber connected Filedi g- 0, 1973 to the conduit for receiving exhaust gas therefrom and an exhaust stack connected to the downstream end of [211 App]' 389380 the secondary chamber. The rotary incinerating chamber is provided with a frustoconical interior surface Cl 110/8 432/105 with the feed end being the smaller diameter end Int. Cl. F23g 5/06 thereof said incinerator chamber being mounted for Field Of Search 1 3 8 rotation about a horizontal axis of rotation for impart- 432/ ing abrasive tumbling movement to waste material feed to said one end by said feed means. The burner is References Cited mounted at the feed end for initiating immediate in- UNITED STATES PATENTS cineration of said waste material and means are pro- 3,306,237 2/1967 Ransom, Jr. 14 Vided at the end Opposite Said one end for removing 3,413,937 12/1968 Bojner et alum. the solid incinerated material therefrom. The secon- 3,436,061 4/1969 Zinn dary combustion chamber includes a burner mounted 3,487,792 I/ 1970 Dixon et a1. for tangential flame discharge at an angle to longitudi- 3,682,117 8/1972 Rousseau nal axis of the chamber to provide a cyclonic aspirat- Porter Et al ga flow through the onduit from the incin rating Primary Examiner-Kenneth W. Sprague Attorney, Agent, or FirmPrutzman, Hayes, Kalb & Chilton chamber. The combustion chamber may be of modular construction.

9 Claims, 4 Drawing Figures PATENTH] JANZI I975 sum 10F 2 PATENTED JANZ] I975 SHEET 2 BF 2 INCINERATION SYSTEM The present invention relates generally to incineration systems for waste and other refuse materials and is more particularly concerned with a new and improved incineration system utilizing a rotary combustion chamber.

Incineration systems have been efficiently utilized heretofore for the disposal of refuse and other waste materials and have included rotary kilns employing a waste tumbling principle. In these systems a rotary kiln or combustion chamber of generally cylindrical configuration either is mounted on a horizontal axis of rotation and employs internal vanes to induce the tumbling action or is mounted on an inclined axis of rotation so as to provide the beneficial effects of a tumbling operation without the necessity for providing such vanes or other tumble inducing devices within the interior of the combustion chamber. The inclined axis of rotation of the rotary kilns induces travel of the waste material along the length of the kiln and has the advantage of providing a natural upward flow pattern for the exhaust gases. However, the completeness of combustion depends to a degree on the precise location of the burner within the combustion chamber and frequently requires a substantially elongated chamber in order to assure full and complete combustion of all of the refuse supplied to the chamber in view of the accelerated movement of the material along the inclined plane. Additionally, large inclined rotary combustion chambers create support problems which tend to promote rapid wear, thus adversely affecting the continuous useful life of the system.

Accordingly, it is an object of the present invention to provide a new and improved self-contained incineration system having a substantially more compact and more simplified construction that efficiently utilizes the tumbling principle of the inclined rotary kiln incinerators while obviating many of the adverse characteristics thereof.

Another object of the present invention is to provide a new and improved incineration system of the type described that provides for rotation of the combustion chamber about a horizontal axis thereby eliminating substantially all of the high wear, thrust-bearing loads associated with rotary kilns having an inclined axis of rotation while retaining the beneficial exhaust gas flow pattern and providing a more compact incinerating zone.

Still another object of the present invention is to provide a compact incineration unit of the type described that combines horizontal rotation of the combustion chamber with a conical interior configuration so as to provide more efficient combustion of therefuse materials supplied thereto. Included in this object is the provision for immediate initiation of the incineration process as the material is fed to the input end of the rotating combustion chamber and a continuous abrasive or grinding action applied to the refuse during the burning operation to reduce the particle size thereof and expose fresh surfaces thereof to insure complete combustion of the waste material.

A further object of the present invention is to provide a new and improved incinerator system of the type described employing an afterburner chamber utilizing a centrifugal aspirator effect that assures complete sterilizing combustion of the gases within the flue to provide substantially smoke-free and odor-free effluent in full compliance with pollution control guidelines for incinerator installations.

A still further object of the present invention is to provide an incineration system well-suited to the provisions for a modular combustion chamber permitting enlargement or reduction therein to suit the particular requirements of the individual installation. Included in this object is the provision for independently operated modular units that maintain the aforementioned advantageous features without sacrificing efficiency or simplicity of operation.

Another object is to provide an incinerator unit of the type described that is of economical yet durable construction and well suited to installation where smaller nonmunicipal use is contemplated.

Other objects will be in part obvious and in part pointed out in more detail hereinafter.

These and related objects are achieved by providing an incinerator unit having a rotary incinerating chamber, a burner for directing flame into said chamber, feed means at one end of the chamber and an exhaust conduit for removing combustion gases from said chamber, the rotary incinerating chamber being provided with a frustoconical surface with said one end being the smaller diameter end thereof, said chamber being mounted for rotation about a horizontal axis of rotation for imparting abrasive tumbling movement to waste material feed to said one end by said feed means, said burner being mounted at said one end for initiating immediate incineration of said waste material and means at the end opposite said one end for removing the solid incinerated material therefrom.

A better understanding of the objects, advantages, features, properties and relationships of the invention will be obtained from the following detailed description and accompanying drawings which set forth certain illustrative embodiments and are indicative of the various ways in which the principles of the invention are employed.

A BRIEF DESCRIPTION OF THE DRAWINGS In the drawings:

FIG. 1 is a perspective view of a compact, selfcontained incinerator unit embodying the features of the present invention.

FIG. 2 is an enlarged side elevation view of the incinerator of FIG. 1 partially broken away and partially in section.

FIG. 3 is a sectional view of the secondary of afterburner combustion chamber of the system of FIG. 1 illustrating the aspirator combustion effected therein, and;

FIG. 4 is a sectional view of a modified embodiment of the primary combustion zone of the incinerator chamber of the present invention.

DESCRIPTION OF A PREFERRED EMBODIMENT Referring now to the drawing in greater detail wherein like reference numerals indicate like parts throughout the several figures, it will be noted the compact, self-contained incinerator unit 10 of the present invention consists essentially of a primary refuse incinerating chamber 12 of increasing diameter from its feed end toward its discharge end and a secondary or afterburner chamber 14 of cylindrical configuration connected to the primary by a gas flue 16, the chamber 14 communicating with an exhaust stack 18 for discharge of pollution-free effluent. As best seen in FIG. 2, the primary combustion chamber 12 of the system is provided with a frustoconical interior configuration and is mounted for rotation about a horizontal axis of rotation within an appropriately configured enclosure of housing 20. The housing includes a front wall member 22 having an enlarged circular panel 24 mounted centrally thereon and an inwardly facing recess 26 extending around the periphery of the panel for receiving the feed end of chamber 12. The panel 24 extends into the chamber 12 and is provided with a radially outwardly extending flange 28 abutting the exterior of wall member 22 to sealably enclose the feed end of the chamber 12. A refuse or waste inlet chute 30 is mounted on the panel and communicates with the interior of the primary combustion chamber 12 for feeding raw waste material thereto for incineration. The chute 30 is radially offset to one side of the circular panel 24 and therefore to one side of the chambers horizontal axis of rotation so that the refuse as supplied to the interior of the combustion chamber 12 will be immediately subjected to the tumbling action of the rotating chamber. As shown, a burner mount 32 also is secured to the front panel 24 at a location that is radially offset from the center of the panel on the opposite side of the axis of rotation from the waste chute 30 and in substantiall side-by-side relationship therewith. In this manner, the flame projecting from the burner 34 in mount 32 is not smothered by fresh quantities of waste material added to the combustion zone but is in a position to immediately initiate the incineration action thereon.

Suitable drive means such as a motor 36, is mounted immediately adjacent the front wall 22 of the incinerator unit within enclosure portion 38 and is illustrated as provided with a drive gear 40 which drivably meshes with a driven gear 42 secured to the cylindrical exterior of the frustoconical combustion chamber 12. In this connection it should be noted that the exterior surface of chamber 12 also may be of any suitable configuration such as frustoconical although the cylindrical configuration illustrated is preferred.

The chamber 12 is also provided with a pair of axially spaced guidetracks 44 along which travel the supporting and guiding rollers 46 mounted on suitable supports 48 secured to a floor 50 or other suitable base. The supporting rollers 46 and tracks 44 are located near opposite ends of the chamber 12 and maintain the chamber in an appropriate position for horizontal rotation about the longitudinal axis of the frustoconical interior walls thereof.

It is an important feature of the present invention that the interior of the combustion chamber 12 exhibits this desired frustoconical configuration with the smaller diameter thereof located at the burner and feed end of the combustion chamber. The taper on the walls of the frustoconical chamber is not substantial although the degree of taper may be changed to suit the particular application to which the incinerator is to be applied. For example, it has been found that good results are obtained for a combustion zone of approximately 4 feet in length with the diameter of the combustion zone tapering from about 32 inches at the small feed end to about 36 inches at the enlarged exit end thereof so that the interior wall exhibits a slope of about 23.

As will be appreciated, rotation of this low slope primary combustion chamber 12 about a horizontal axis of rotation will result in movement of the waste material primarily in a vertical direction as the combustion chamber rotates and will impart to the burning refuse only a minor or slight axial component of movement toward the enlarged end of the combustion chamber 12. This rotating and tumbling action of the refuse during the incinerating process tends to move the larger pieces of unburned material inwardly from the surface of the combustion chamber causing it to tumble or fall in a continuous grinding action until it is reduced to small fully incinerated particles. The smaller particles have a greater tendency to roll as the combustion chamber is rotated and therefore will move down the slope slowly toward the wide end of the combustion chamber with a continuing and constant abrading action. This movement of the material within the combustion chamber is substantially different from that exhibited by particles within a combustion chamber having an inclined axis of rotation since the rotation of the combustion chamber in such a structure causes axial movement of the particle along the chamber as the particles rotate upwardly with the chamber. Thus the action of the horizontal axis of rotation coupled with the frustoconical configuration of the combustion zone permits the utilization of a substantially shorter zone of combustion while at the same time permitting gradual and somewhat slower but more effective movement of the particules toward the ash collection end of the chamber. As can be appreciated, more thorough incineration of the waste material is achieved in a far shorter and more compact combustion zone.

An additional advantage of the frustoconical combustion zone configuration is the fact that the exhaust gases naturally rise and flow toward the area of greater volume. In accordance with the present invention, the gases are permitted to follow the gradually elevating top surface of the combustion chamber until they reach the flue 16 leading toward a secondary combustion chamber 14 of the system. In the embodiment illustrated, the flue 16 is formed in a rear end wall 52 of the incinerator unit. The wall 52 is spaced slightly from the lowermost end of the combustion chamber to provide a grate-like opening designated by numeral 54, permitting the granulated ash to fall from the enlarged lowermost end of the combustion chamber 12 into a suitable ash collection tray 56 located therebeneath. A clean out door 58 in the bottom of wall 52 provides access to the tray 56 and replacement thereof as required.

, The flue 16 shown as being formed as part of the end wall 52 extends upwardly from adjacent the top of the primary combustion zones exit end and communicates with the secondary combustion chamber 14 of cylindrical configuration. This secondary chamber 14 is mounted on end wall 52 and extends axially above the primary chamber 12 along the length thereof. The secondary chamber 14 mounts an afterburner 60 adjacent the end thereof connected to the flue 16, the afterburner 60 being mounted so as to inject a flame into the secondary chamber 14 at an acute angle tangentially to the interior surface of the secondary combustion chamber. As a result, the flame provides a cyclonic or spiral gas flow therein which aspirates or draws gas into the secondary chamber 14, from the flue l6 and therefore from the primary combustion chamber 12. The aspirated gas is drawn into the cyclonic afterburning flame zone thereby assuring complete combustion of all combustible components carried by the gas. This aspiration effect additionally assures a smooth and continuous gas flow from the primary combustion chamber 12, thus substantially reducing the possibility of gas leakage out of the primary chamber and into the surrounding atmosphere. Additionally, this provides a complete mixing of the exhaust gases from the primary combustion zone 12 and eliminates the possibility of blowbacks therein while also obviating the necessity for fans or other blowing device within the gas stream for trouble-free operation of the incineration procedure.

The exhaust from the afterburner 60 is directed to an exhaust stack 18 mounted on the front end wall 22 and connected to the exit end of the afterburner chamber 14. The stack 18 is of conventional design and may include a scrubbing unit (not shown) or other suitable exhaust cleansing unit for treating the effluent prior to its release into the atmosphere.

It is a further feature of the present invention that the primary and/or secondary combustion zones of the incinerator system may be readily adapted to a modular drum construction such as the modular primary combustion chamber 62 illustrated in FIG. 4. The modular configuration of that chamber is such that the internal frustoconical design is retained and is continuous from one modular section to the next. This permits the addition of a modular section on either end of an existing combustion chamber in order to suit the particular needs of the individual installation. The specific modules 64, 66, and 68 of chamber 12 are illustrated as being adapted for individual mounting and may also be coupled to provide a separate drive for each section. If desired, provision also can be made for the removal of ash from each section, such as by the grate-like openings 70 so as to obviate the need of transporting the ash along the entire length of the combustion zone made up of several modular sections. This is permissable because of the low gas leakage resulting from the aspirating effect of the afterburner, thus substantially reduc ing the possibility of gas leakage from the spaces 70 provided for the ash collection. Each modular section of the combustion zone 62 is constructed in a manner similar to the frustoconical zone 12 of FIG. 2 and preferably would be provided with a concrete liner having a smooth, arcuate and continuous inner surface.

Thus as can be seen, the incinerator system of the present invention provides optimum reduction in both weight and volume of waste material coupled with simplicity and economy of operation while assuring clean, pollution-free exhaust from the system. As will be appreciated the system may include suitable automatic or semiautomatic controls or may be controlled manually by a single operator. The operator need simply charge the waste through the charging door or chute 30 and the rotating and incinerating action will proceed automatically without operator participation. Suitable sensors (not shown) may indicate when the incinerator is ready for recharging and/or ash collection. As will be appreciated, the walls of the combustion zones are lined with high temperature refractory material suitable to operation within the temperatures to which the incinerator is subjected such as temperatures up to about 3,000F. Under normal operating conditions, an incinerator having overall dimensions of about 6 feet X6 feet X9 feet is capable of handling about 500 pounds of waste per hour within a unit having a burning chamber working capacity of about 100 cubic feet.

As will be apparent to persons skilled in the art, various modifications, adaptations, and variations of the foregoing specific disclosure can be made without departing from the teaching of the present invention.

I claim:

1. In an incinerator unit, a rotary incinerating chamber, a burner for directing flame into said chamber, feed means at one end of the chamber and an exhaust conduit at the opposite end of said chamber for removing combustion gases therefrom, said combustion chamber including at least one chamber section provided with a generally cylindrical exterior surface and a frustoconical interior surface with said one end being the smaller diameter end thereof, said chamber being mounted for rotation about a horizontal axis of rotation for imparting abrasive tumbling movement to waste material feed to said one end by said feed means, said burner being mounted at said one end for initiating im mediate incineration of said waste material, said unit including means at said opposite end for removing solid incinerated material therefrom.

2. The incinerator of claim 1 wherein the feed means and the burner'are radially offset from the horizontal axis of rotation of said incinerating chamber and the exhaust conduit is positioned adjacent said opposite end of said combustion chamber.

3. In an incinerator unit, a rotary incinerating chamher, a burner for direction flame into said chamber, feed means at one end of the chamber and an exhaust conduit at the opposite end of said chamber for removing combustion gases therefrom, said combustion chamber being provided with a frustoconical interior surface with said one end being the smaller diameter end thereof, said chamber being mounted for rotation about a horizontal axis of rotation for imparting abrasive tumbling movement to waste material feed to said one end by said feed means, said burner being mounted at said one end for initiating immediate incineration of said waste material, said unit including a secondary combustion chamber connected to the conduit for receiving exhaust gas therefrom, said secondary combustion chamber being provided with gas flow control means adapted to provide a cyclonic aspirating gas flow therethrough.

4. The incinerator of claim 3 wherein the secondary chamber is cylindrical and the gas flow control means includes a burner mounted for tangential flame discharge at an acute angle to the longitudinal axis of said cylindrical secondary chamber.

5. The incinerator of claim 1 wherein said incinerating chamber is comprised of a plurality of modular chamber sections.

6. The incinerator of claim 5 wherein said modular sections provide a continuous frustoconical configuration throughout the interior of said chamber.

7. The incinerator of claim 1 wherein said feed means includes a feed chute positioned predominantly to one side of the incinerating chambers axis of rotation and the burner is radially spaced from the axis of rotation and on the opposite side thereof from the feed chute.

8. The incinerator of claim 1 wherein said combustion chamber slopes from said one end at an angle of about 2-3.

9. In an incinerator unit, an elongated rotary incinerating chamber having an enlarged discharge end for gas exhaust and ash discharge, a burner positioned at the end of the chamber opposite said enlarged discharge end for directing flame into said chamber generally toward said discharge end, a plurality of supports spaced wall, said longitudinal axis being coincident with said horizontal axis of rotation to substantially eliminate all thrust bearing loads acting on said horizontal drive shaft and said supports while promoting natural flow of the exhaust gas and ash discharge toward said enlarged discharge end. 

1. In an incinerator unit, a rotary incinerating chamber, a burner for directing flame into said chamber, feed means at one end of the chamber and an exhaust conduit at the opposite end of said chamber for removing combustion gases therefrom, said combustion chamber including at least one chamber section provided with a generally cylindrical exterior surface and a frustoconical interior surface with said one end being the smaller diameter end thereof, said chamber being mounted for rotation about a horizontal axis of rotation for imparting abrasive tumbling movement to waste material feed to said one end by said feed means, said burner being mounted at said one end for initiating immediate incineration of said waste material, said unit including means at said opposite end for removing solid incinerated material therefrom.
 2. The incinerator of claim 1 wherein the feed means and the burner are radially offset from the horizontal axis of rotation of said incinerating chamber and the exhaust conduit is positioned adjacent said opposite end of said combustion chamber.
 3. In an incinerator unit, a rotary incinerating chamber, a burner for direction flame into said chamber, feed means at one end of the chamber and an exhaust conduit at the opposite end of said chamber for removing combustion gases therefrom, said combustion chamber being provided with a frustoconical interior surface with said one end being the smaller diameter end thereof, said chamber being mounted for rotation about a horizontal axis of rotation for imparting abrasive tumbling movement to waste material feed to said one end by said feed means, said burner being mounted at said one end for initiating immediate incineration of said waste material, said unit including a secondary combustion chamber connected to the conduit for receiving exhaust gas therefrom, said secondary combustion chamber being provided with gas flow control means adapted to provide a cyclonic aspirating gas flow therethrough.
 4. The incinerator of claim 3 wherein the secondary chamber is cylindrical and the gas flow control means includes a burner mounted for tangential flame discharge at an acute angle to the longitudinal axis of said cylindrical secondary chamber.
 5. The incinerator of claim 1 wherein said incinerating chamber is comprised of a plurality of modular chamber sections.
 6. The incinerator of claim 5 wherein said modular sections provide a continuous frustoconical configuration throughout the interior of said chamber.
 7. The incinerator of claim 1 wherein said feed means includes a feed chute positioned predominantly to one side of the incinerating chamber''s axis of rotation and the burner is radially spaced from the axis of rotation and on the opposite side thereof from the feed chute.
 8. The incinerator of claim 1 wherein said combustion chamber slopes from said one end at an angle of about 2*-3*.
 9. In an incinerator unit, an elongated rotary incinerating chamber having an enlarged discharge end for gas exhaust and ash discharge, a burner positioned at the end of the chamber opposite said enlarged discharge end for directing flame into said chamber generally toward said discharge end, a plurality of supports spaced along said chamber for supporting said chamber for rotation about a horizontal axis, and drive means including a horizontal drive shaft for rotatably driving said chamber on said supports, said chamber including at least one longitudinally extending chamber section having an interior chamber wall of frustoconical configuration, said chamber being rotated by said drive means about the longitudinal axis of said frustoconical wall, said longitudinal axis being coincident with said horizontal axis of rotation to substantially eliminate all thrust bearing loads acting on said horizontal drive shaft and said supports while promoting natural flow of the exhaust gas and ash discharge toward said enlarged discharge end. 